Results 111 to 120 of about 40,430,947 (286)
Shiyou jixie, 2015 在深水测试过程中，测试管柱下入井后其受力和变形无法观测，密封插管长度的不合理设置会造成封隔器密封失效及井下管柱永久变形等严重事故。为保障深水测试作业安全高效实施，对深水井下管柱轴向变形原理和规律进行研究，形成密封插管安全长度确定方法，并以我国南海某深水井为对象进行实例分析。计算结果表明，不同作业工况下测试管柱轴向变形相差较大，开井作业测试管柱的伸长量随着测试产量的增加而增加，温度和压力是深水井下测试管柱轴向变形的主要影响因素；建议选择关井后密封插管相对开井作业的上移距离为密封插管安全长度的参考值 ...
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野生动物学报, 2020 本研究以12个鸟类物种为研究对象，采用全谱直读电感耦合等离子体发射光谱法（ICPOES法）测定样品中的微量元素，并对其元素的组成和含量进行分析研究。分析结果表明，17份卵壳样品中Ca 元素的含量最高，S、Na、P、Sr、Mg、K含量较高，Zn、Ce、Cu、Ta只有极少数物种的卵壳检出微量。元素检测结果采用软件IBM SPSS Statistics 22中的系统聚类法，根据元素含量对样品进行物种聚类分析，利用变异数分析法对聚类后分组物种进行元素的组间差异显著性分析。由聚类图可见 ...
孙冬婷 1 +3 more
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Diversity and complexity in neural organoids
FEBS Letters, EarlyView.Neural organoid research aims to expand genetic diversity on one side and increase tissue complexity on the other. Chimeroids integrate multiple donor genomes within single organoids. Self‐organising multi‐identity organoids, exogenous cell seeding, or enforced assembly of region‐specific organoids contribute to tissue complexity.
Ilaria Chiaradia, Madeline A. Lancaster
wiley +1 more source
Shiyou jixie, 2015 为了避免钻井隔水管在深海环境中出现涡激振动现象，利用ANSYS软件，针对带浮力块和不带浮力块的隔水管系统进行了模态分析。定量研究了浮力块密度、长度及不同布置位置对隔水管固有频率的影响。研究结果表明，布置浮力块后隔水管的各阶固有频率都会相应增大；当隔水管布置浮力块的长度与起始位置相同时，随着浮力块密度的增大，隔水管的各阶固有频率值相应减小；当布置浮力块的密度与长度相同，且布置浮力块的位置靠近隔水管的下端时，隔水管的各阶固有频率越小；当布置浮力块的密度与起始布置位置相同时 ...
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An isoform of 14‐3‐3 protein regulates transbilayer lipid movement at the plasma membrane
FEBS Letters, EarlyView.Loss of 14‐3‐3ζ in CHO cells confers resistance to exogenous phosphatidylserine (PS) and impairs endocytosis‐independent inward flip‐flop of fluorescent PS at the plasma membrane. RNAi‐mediated knockdown reproduces this defect, while no additive effect is seen in ATP11C‐deficient cells.
Akiko Yamaji‐Hasegawa +3 more
wiley +1 more source
Shiyou jixie, 2014 在油气田压裂等储层改造过程中，高速携砂液流动会使管柱壁面受到冲刷腐蚀影响，造成材料流失，威胁井筒安全。为此，结合数值模拟与喷射式冲蚀试验，分析超级13Cr不锈钢材料受冲刷腐蚀影响规律，利用DPM离散相模型追踪固体颗粒撞击材料表面的速度与角度，为研究不锈钢表面受撞击后的抗腐蚀特性提供流体力学参数。研究结果表明，不锈钢材料在含Cl-纯液相介质中能够生成钝化膜以保护基体材料；超级13Cr材料在流速9 m/s常温条件下流动水介质中，开路电位稳定，材料在高速流动液相中具有较强的抗腐蚀能力 ...
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Atmospheric neutrinos in Soudan 2.
, 1999 The value and zenith angle dependence of the atmospheric neutrino flavor ratio is interpreted as evidence for neutrino oscillations. The latest values from the Soudan 2 detector are presented.
Soudan 2 Collaboration +2 more
core
FEBS Letters, EarlyView.Plasma membranes contain dynamic nanoscale domains that organize lipids and receptors. Because viruses operate at similar scales, this architecture shapes early infection steps, including attachment, receptor engagement, and entry. Using influenza A virus and HIV‐1 as examples, we highlight how receptor nanoclusters, multivalent glycan interactions ...
Jan Schlegel, Christian Sieben
wiley +1 more source
Shiyou jixie, 2014 针对深海深层油气资源的勘探开发不断深入，海洋勘探对深海工程装备的勘探井深要求提高的现状，研制了9 000 m自升式海洋井架。该井架采用直立无绷绳、多节套装、自升式、K形结构，自带起升绞盘，安装方便且占地面积小。井架采用小模块设计，每个模块总质量小于17 t，满足海洋平台现场吊装要求。井架本体及关键受力部件采用热喷铝防腐处理及喷涂海洋防腐油漆工艺，满足海洋环境防腐要求。井架载荷试验结果表明，在最大试验载荷6 750 kN时，井架最大应力部位的应力值为148.2 MPa，该部位井架材料屈服强度为325.0 ...
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FEBS Letters, EarlyView.Ascidian Ciona larvae initially show strong clockwise tail twisting, which is largely corrected during development. However, a small residual twist remains. This study shows that organized helical myofibrils in tail muscles mechanically stabilize this residual asymmetry, preventing complete restoration of bilateral symmetry and revealing how embryos ...
Yuki S. Kogure +3 more
wiley +1 more source